code: def get_servers(server: Union[str, List[str], None]) -> List[str]:
      if not server:
          return list(Configs.get().servers.keys())
      elif type(server) is str:
          return [server]
      else:
          return server
  
file_path: labml/remote/labml_remote/cli/util.py
imports: from typing import Union, List, Tuple, Optional
  import click
  from labml.logger import Text
  from labml_remote.configs import Configs
  from labml_remote.job import JOBS, Job
  from labml_remote.server import SERVERS
label_desc: Use image node_id 1 for calling a global function with example usage: get_servers(server) and returns: list, list, server